Electrolytic corrosion is caused by forcing DC current to flow between two metal objects immersed in an electrolyte such as sea water. The source of current causing corrosion can be the DC battery system or it can occur naturally due to the chemical composition of the two metal parts in question. The former is usually called electrolytic corrosion and the latter galvanic corrosion. The device is aimed at the former not the latter. But the mechanism of corrosion is the same in either case.

However, the device they are promoting might actually work as a way to identify sources of stray forced current. It does nothing to eliminate that stray current as far as I can tell. You have to eliminate the source of leakage current yourself. I have my doubts that a lay boater could use this device effectively. They claim a guarantee of success in many places of their literature. That usually makes me suspicious but that's just me.

There are lots of posts on this and the subject has been covered in many sailing magazines. (Practical Sailor) If you spend some time researching this you will probably learn enough to become dangerous. There are especially some things you can do to discover likely problems in marinas and even locate the source-boat wreaking havoc on every one else. I read some posts by surveyors and Elecrical nerds that tell you how to buy the components to use with your multimeter to to build your own tool. Good Hunting.

I'm with Nicholson. This is a tool to use to discover stray current corrosion. Yes, there is some good info on the site.

But the person selling this is showing their own ignorance of the problem and what they can accomplish with this device. First off it is not electrolysis. Professionals that deal with corrosion problems call this stray current corrosion, as opposed to galvanic corrosion and various other types of corrosion. see New Boatbuilders Home Page - Corrosion On Boats